At what age is a child expected to have 50% of their speech understandable to strangers?

By 24 months, a child is typically expected to have around 50% of their speech understandable to strangers. This milestone indicates significant progress in language development, including vocabulary expansion and clarity of speech. At this age, children usually start combining words into simple sentences and are able to articulate familiar words more clearly, giving them the ability to communicate basic needs and ideas to those outside their immediate family.

This milestone is a reflection of cognitive and social development as well, as children begin to engage in more complex interactions with peers and adults. In contrast, understanding of speech from children younger than 24 months generally remains limited; by 12 months, for example, a child's speech is largely characterized by single words and may not be easily understood by unfamiliar listeners. Thus, the expectation of 50% intelligibility aligns with the general developmental trajectory observed around the age of 2.